code: def _main():
      ps = mp.Process(target=w)
      ps.start()
      ps.join()
  
file_path: MONAI/tests/test_loader_semaphore.py
imports: from __future__ import annotations
  import multiprocessing
  import unittest
  import monai
label_desc: Use image node_id 2 for calling a global function with example usage: _main() without return types